The present invention relates to power converters for recreational vehicles and the like, and in particular to a concept for mounting the electrical components of the converter in a housing.
Recreational vehicles, such as motor homes, vans, campers, trailers and the like, are typically equipped with an electrical system for operating lights and other applicances, which is compatible with and operates off of the standard electrical power system of the vehicle. Generally, such vehicles have a 12 volt DC electrical system, and include at least one storage battery, and an alternator and/or generator which charges the battery and is driven by the vehicle engine. When the vehicle engine is in operation, such as when the vehicle is being driven on the highway, or is idling, the electrical appliances of the recreational vehicle are powered by the vehicle's 12 volt battery system. When the vehicle engine is not operating, such as when the vehicle is in a parked or stored condition, the continued use of the vehicle's electrical appliances will drain the battery's electrical charge, and eventually completely discharge the battery. Although the storage battery can often be recharged, the amount of discharge is often sufficient to prevent the starting of the vehicle engine; thereby severely inconveniencing the user. Further, repeatedly discharging the battery to a very low level can permanently damage the storage battery and greatly reduce its operating life. Although the vehicle engine can be started periodically to recharge the battery, such a procedure is quite inconvenient, inefficient, and often hazardous due to the engine's emission of toxic gases, particularly carbon monozide. To alleviate these problems, recreational vehicles are sometimes equipped with a separate electrical generator. However, such generators are quite expensive, increase the total weight of the vehicle, and do not completely eliminate the hazard of exposure to toxic exhaust gases.
Recreational vehicles have also been provided with transformers or converters to power the vehicle's electrical system by a conventional 110 VAC source of household current when the vehicle engine is not operating and the vehicle is located near a suitable electrical source. These devices convert the household 110 VAC source to a 12 volt DC current which is compatible with the vehicle'electrical system and the associated appliances. In this manner, when the recreational vehicle is immobile, such as when the same is parked at a camp site having electrical outlets available, the 110 VAC source can be connected with the transformer and the electrical appliances in the vehicle can be operated without draining the vehicle's storage battery or requiring the vehicle engine to be started.
Such converters typically include the basic elements of a transformer, a rectifier, and a fuse or circuit breaker, all of which are encased in a housing which is mounted inside the recreational vehicle. The housing generally comprises a two-part construction with a concave base and a relatively flat cover plate to which the various electrical components are mounted. The installation of such units is achieved by providing an aperture in a selected wall of the vehicle, mounting the concave base therein, threading the vehicle's electrical service wires through the concave base and connecting the same with the converter components which are mounted on the housing cover plate, and inserting the cover plate with components thereon into the concave base, and interconnecting the two housing members. Because the cover plate supports a rather heavy transformer, as well as the other electrical components, the same requires a very rigid construction which is typically fabricated from a metal plate. However, the use of such conductive materials presents an electrical safety hazard. Further, the attachment of the components to the cover plate requires a plurality of stout metal fasteners, which typically extend through the front cover plate and are connected with the various electrical components of the converter. This type of interconnection requires a substantial amount of assembly time and cost to insure a secure mounting of the converter components onto the front panel, and also defaces the housing and imparts a rather unsightly appearance thereto. This type of interconnection also requires the use of specially designed electrical components, which are provided with custom mountings to mate with the fasteners, and fasteners sufficiently strong to suspend the components on the housing cover. Heretofore, metal fasteners have been used to achieve the required mounting strength, thereby exacerbating the hazard of electrical shock. As a result of the above noted two-part housing construction, heretofore the power converters have been very difficult to repair, are susceptible to damage during installation, and may be tampered with either before or after installation in the vehicle, thereby increasing the manufacturer's exposure to potential liability.
Although in some power converters the electrical components are fastened to the base portion of the housing, the relatively deep sidewalls of the housing which are required to encase the components renders the assembly process quite difficult, time consuming and costly.